Total Joint Arthroplasty in Patients with Obstructive Sleep Apnea: Strategies for Reduction of Perioperative Complications.

Obstructive sleep apnea (OSA) has been associated with increased risk for medical complications following total joint arthroplasty. Our institution employs postoperative precautions for OSA patients in an effort to minimize the impact of postoperative complications in this group. We performed this study to assess the effect of careful monitoring on postoperative complication rates in OSA patients. We identified patients with a clinically suspected or objective diagnosis of OSA who received total joint arthroplasty between January 1998 and January 2008. 1016 cases in 792 OSA patients were matched to 1016 cases in 993 control patients to compare complication rates. There were no differences between OSA and control patients in cardiovascular and respiratory complications following TJA. Patients with OSA experienced increased rates of postoperative acute renal failure when compared with controls (p = 0.02) and experienced mild desaturations (Hb O2 < 92%) (p = 0.002), but not severe desaturations (Hb O2 < 88%) (p = 0.2). We conclude that our postoperative monitoring protocols are successful in reducing postoperative complications most commonly associated with OSA. We were interested to note the increased risk for OSA patients to develop postoperative acute renal failure and believe that future study is warranted to explore the link between OSA and renal failure.

The Otto Aufranc Award: Identification of a 4 Mb region on chromosome 17q21 linked to developmental dysplasia of the hip in one 18-member, multigeneration family.

Developmental dysplasia of the hip (DDH) is a disabling condition that, depending on geography, can afflict between 20% and 80% of patients with end-stage arthritis of the hip. Despite its prevalence, the etiology of this disease remains unknown. DDH is a complex disorder with both environmental and genetic causes. Based on the literature the candidate genes for the disease are HOXB9, collagen type I alpha1, and DLX 3. The purpose of our study was to map and characterize the gene or genes responsible for this disorder by family linkage analysis. We recruited one 18-member, multigeneration affected family to provide cheek swabs and blood samples for isolation of DNA. Amplified DNA underwent a total genome scan using GeneChip Mapping 250 K Assay (Affymetrix, Santa Clara, CA). We observed only one region with a LOD score greater than 1.5: a 4 Mb region on chromosome 17q21.32, yielding a LOD score of 1.82. While a LOD score of 1.82 does not meet the accepted standard for linkage we interpret these data as suggesting the responsible gene could be linked to this region, which includes a cluster of homeobox genes (HOX genes) that are part of the developmental regulatory system providing cells with specific positional identities along the developing joint and spine. Discovering the genetic basis of the disease would be an important step in understanding the etiology of this disabling condition.

Aggressive Anticoagulation after TJA: an evaluation of the ACCP guidelines for Thromboprophylaxis.

Thromboembolic disease is common after orthopaedic surgery. In an effort to minimize the risk of pulmonary embolism and deep vein thrombosis (DVT), anticoagulation administration has become a common practice. Both the American College of Chest Physicians (ACCP) and the American Association of Orthopaedic Surgeons (AAOS) have published guidelines recommending antithrombotic protocols. The ACCP guidelines are excessive and do not adequately evaluate the complications resulting from aggressive anticoagulation. These complications include, but are not limited to, major and minor bleeding events, thrombocytopenia, subsequent periprosthetic infection, and complications with spinal or epidural anesthesia. The AAOS guidelines generated by a group of orthopedic surgeons evaluate the efficacy of various agents in preventing pulmonary embolus and not distal DVT. They differ from the AACP guidelines in some aspects. The AAOS guidelines accept the use of aspirin combined with mechanical compression devices, and low-dose warfarin therapy. We believe that the AAOS guidelines for thromboprophylaxis take into account all risks associated with anticoagulation therapy and may prove to be a safer option for our patients.